This invention relates generally to a sealing element fitted on the neck of a liquid container to which a closure member or a dispensing element is secured, and more particularly to such a sealing element which isolates the closure member or dispensing element from the attachment means of the sealing element.
U.S. Pat. No. Re. 29,850 to Labarre discloses a sealing element of the general type involved herein as being fitted on a bottle neck and having a removable overcap engageable therewith. The sealing element is in the form of a closure having a sealing and tamperproof diaphragm extending across the mouth of the bottle which is capable of being torn open to facilitate pouring of the liquid product from the bottle. Experience has shown that leakages will occur between the closure and the bottle and after removing the sealing diaphragm between the overcap and the closure especially as the result of dimensional and/or shape irregularities in the bottle neck which impose distortions on the snap bead for the overcap and upon the interface on the reseal elements between the closure and the overcap. Thus, with tight fitting bottle finishes, the skirts engaging the inner and outer walls of the bottle neck are apt to distort causing leakage between the bottle and the closure, and these distortions have a tendency to shift the pouring spout out-of-round or to otherwise distort thereby causing leakages between the reseal surfaces of the closure and the overcap. The snap bead is also likely to become distorted so as to affect the reseal engagement between the reseal surfaces when the overcap is snap-fitted in place. It should be pointed out that the bottle irregularities referred to here include, without limitation, aberrations in the outer diameter and/or inner diameter of the bottle neck, an out-of-round contour of the mouth of the bottle, non-concentric outer diameter and inner diameter walls of the bottle neck, height of retention bead, etc. Such bottle finish irregularities frequently occur during the molding of glass or plastic bottles.